Centrifugal pump with intermittent discharge



March 29, 1949. R. H. GODDARD 2,465,527

CENTRIFUGAI.:l PUMP WITH INTERMITTENT DISCHARGE Filed Feb. l, 1947 Patented Mer. 29, 1949 CENTRIFUGAL PUMP WITH INTERMITTENT' DISCHARGE Robert H. Goddard, deceased, late of Annapolis,

Md., by Esther C. Go ter, Mass., assignor o ddard, executrix, Worcesf one-half to The Daniel and Florence Guggenheim Foundation, New York, N. Y., a corporation of New York Application February 1, 1947, Serial No. 725,803

1 Claim. l

This invention relates to a centrifugal pump particularly adapted for use in feeding combustion liquids to a rocket-type combustion chamber.

It is the general object of this invention to provide a centrifugal pump by which an interrupted or pulsating flow of a combustion liquid may be produced. Such interrupted flow, combined with simultaneous ignition, results in a great number of small but veryV eilicient detonations.

To the attainment of this general object, a centrifugal pump is provided in which the outward discharge of the rotor is interrupted several times during each rotation of said rotor.

The invention further relates to arrangements and combinations of parts which will be hereinafter described and more particularly pointed out in the appended claim.

A preferred form of the invention is shown in the drawings, in which Fig. 1 is a sectional side elevation of a centrifugal pump embodying this invention;

Fig. 2 is a transverse sectional elevation, taken along the line 2-2 in Fig. l;

Fig. 3 is a sectional side elevation similar to Fig. l but showing the parts in a different operative relation; and

Fig. 4 is a perspective viewshowing a pair of centrifugal pumps and a single driving turbine.

Referring to Figs. 1 to 3. the improved centrifugal pump comprises a two-part casing I in which a rotor Il is rotated by a driving shaft I2. The rotor il has a plurality of blades I4 separated by discharge passages i5.` The blades and passages are preferably of the same circumferential length at the periphery of the impeller and the blades It are preferably made hollow for lightness. as indicated at i6.

The casing i0 has a chamber 20 in which the rotor il revolves vwith close clearance. The chamber is surrounded by an outwardly expanding discharge passage 2l and by a spiral volute 22, which volute is discharged through an outlet pipe 24.

One part of the casing i0 is provided with la plurality of segmental closure members 30, extending across the chamber 20 and just clearing the ends of the impeller arms or blades I4.

The liquid to be pumped is supplied at the axis of the pump through a feed pipe 33 (Fig. 2) and flows freely into the passages I5 between the im- .peller blades i4. The liquid tends to move outward along the passages l5 in the usual way under the inuence of centrifugal force, and when the blades i4 are in the position shown in Fig. 3, 55

the liquid is freely discharged through the passage 2i and volute 22 into the outlet pipe 2l.

When, however, the blades I4 are in the position shown in Fig. 1, such outward flow is obstructed, as the outer ends of the passages I5 are closed by the segmental closure members 30. The discharge of the pump is thus interrupted every time the impeller reaches the position shown in Fig. l, and flow again takes place every time the impeller reaches the position shown in Fig. 3.

An interrupted or pulsating disch-arge thus takes place through the outlet pipe 24, and the frequency of interruption depends on the number of blades on the impeller, taken in connection with the speed of rotation thereof.

In Fig. 4, two pumps P and P' are shown mounted on a single driving shaft and rotated by a single fluid-operated turbine T. With this combina-tion, two combustion liquids may be fed intermittently to a single combustion chamber, and the interruptions of feed may be caused to take place simultaneously and at equal time intervals.

Having been thus described. the invention is not to be limited to the details herein disclosed, otherwise than as set forth in the claim, but what is claimed is:

A centrifugal pump for effective delivery of liquid in quantity and having a two-partcasing and an impeller rotatably mounted in said casing and having an even number of wide-end blades extending from adjacent the axis to the periphery of said impeller and an equal number of'alternating outwardly expanding delivery passages of substantially the same peripheral length at their outer ends and extending fromadjacent the axis -to the periphery of said impeller, and an equal number or thin segmental shields mounted on one part of said casing and extending across said casing and closely clearing the periphery of said impeller, and said shields being of substantially the same peripheral length as said blades and said passages.

ESTHER C. GODDARD, Erecutrx of the Last Will and Testament o! Robert H. Goddard, Deceased.

REFERENCES CITED FOREIGN PATENTS Country Date Great Britain Oct. 26. 1938 Number 

